From 46aed5800f7989f47bc134c6cd06124b11600087 Mon Sep 17 00:00:00 2001
From: Lance Ball <lball@redhat.com>
Date: Wed, 22 Nov 2017 13:49:50 -0500
Subject: [PATCH] test: make common.mustNotCall show file:linenumber
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When a test fails via `common.mustNotCall` it is sometimes hard to
determine exactly what was called. This modification stores the
caller's file and line number by using the V8 Error API to capture
a stack at the time `common.mustNotCall()` is called. In the event
of failure, this information is printed.

This change also exposes a new function in test/common, `getCallSite()`
which accepts a `function` and returns a `String` with the file name and
line number for the function.

Backport-PR-URL: https://github.com/nodejs/node/pull/19355
PR-URL: https://github.com/nodejs/node/pull/17257
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Khaidi Chu <i@2333.moe>
---
 test/common/README.md                      |  6 +++
 test/common/index.js                       | 44 +++++++++++++++++++++-
 test/parallel/test-common-must-not-call.js | 26 +++++++++++++
 3 files changed, 75 insertions(+), 1 deletion(-)
 create mode 100644 test/parallel/test-common-must-not-call.js

diff --git a/test/common/README.md b/test/common/README.md
index 4e7e955487bd3f..8a6ce5f60456c5 100644
--- a/test/common/README.md
+++ b/test/common/README.md
@@ -94,6 +94,12 @@ Path to the 'fixtures' directory.
 
 Returns an instance of all possible `ArrayBufferView`s of the provided Buffer.
 
+### getCallSite(func)
+* `func` [&lt;Function>]
+* return [&lt;String>]
+
+Returns the file name and line number for the provided Function.
+
 ### globalCheck
 * [&lt;Boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type)
 
diff --git a/test/common/index.js b/test/common/index.js
index 7747cb57cf3ae7..d762f4e0aa8498 100644
--- a/test/common/index.js
+++ b/test/common/index.js
@@ -480,9 +480,51 @@ exports.fileExists = function(pathname) {
   }
 };
 
+exports.canCreateSymLink = function() {
+  // On Windows, creating symlinks requires admin privileges.
+  // We'll only try to run symlink test if we have enough privileges.
+  // On other platforms, creating symlinks shouldn't need admin privileges
+  if (exports.isWindows) {
+    // whoami.exe needs to be the one from System32
+    // If unix tools are in the path, they can shadow the one we want,
+    // so use the full path while executing whoami
+    const whoamiPath = path.join(process.env['SystemRoot'],
+                                 'System32', 'whoami.exe');
+
+    let err = false;
+    let output = '';
+
+    try {
+      output = execSync(`${whoamiPath} /priv`, { timout: 1000 });
+    } catch (e) {
+      err = true;
+    } finally {
+      if (err || !output.includes('SeCreateSymbolicLinkPrivilege')) {
+        return false;
+      }
+    }
+  }
+
+  return true;
+};
+
+exports.getCallSite = function getCallSite(top) {
+  const originalStackFormatter = Error.prepareStackTrace;
+  Error.prepareStackTrace = (err, stack) =>
+    `${stack[0].getFileName()}:${stack[0].getLineNumber()}`;
+  const err = new Error();
+  Error.captureStackTrace(err, top);
+  // with the V8 Error API, the stack is not formatted until it is accessed
+  err.stack;
+  Error.prepareStackTrace = originalStackFormatter;
+  return err.stack;
+};
+
 exports.mustNotCall = function(msg) {
+  const callSite = exports.getCallSite(exports.mustNotCall);
   return function mustNotCall() {
-    assert.fail(msg || 'function should not have been called');
+    assert.fail(
+      `${msg || 'function should not have been called'} at ${callSite}`);
   };
 };
 
diff --git a/test/parallel/test-common-must-not-call.js b/test/parallel/test-common-must-not-call.js
new file mode 100644
index 00000000000000..d70daabf0a4bd0
--- /dev/null
+++ b/test/parallel/test-common-must-not-call.js
@@ -0,0 +1,26 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const path = require('path');
+
+const message = 'message';
+const testFunction = common.mustNotCall(message);
+
+const validateError = common.mustCall((e) => {
+  const prefix = `${message} at `;
+  assert.ok(e.message.startsWith(prefix));
+  if (process.platform === 'win32') {
+    e.message = e.message.substring(2); // remove 'C:'
+  }
+  const [ fileName, lineNumber ] = e.message
+                                    .substring(prefix.length).split(':');
+  assert.strictEqual(path.basename(fileName), 'test-common-must-not-call.js');
+  assert.strictEqual(lineNumber, '8');
+});
+
+try {
+  testFunction();
+} catch (e) {
+  validateError(e);
+}